骨外黏液样软骨肉瘤2例临床病理学特征

Diagnosis and differential diagnoses of extraskeletal myxoid chondrosaroma

目的探讨骨外黏液样软骨肉瘤(EMC)的临床病理学特征。方法报道2例EMC的组织形态学和免疫组化特征,结合文献对其病理诊断和鉴别诊断进行分析。结果 2例EMS分别发生于左侧腹壁和右臀部。光镜下肿瘤呈多结节状,结节又分隔成大小不等的小叶,类圆形、梭形、星芒状肿瘤细胞包埋于黏液样基质中,肿瘤细胞具轻度异型性。免疫组化示vimentin和S-100为(+),Ki-67阳性率<2%。结论 EMC分为分化好的普通型和分化差的细胞型,两型均具有特异的组织学和细胞遗传学改变,免疫表型特异,Ki-67阳性率对预后有影响。

Purpose To investigate the clinicopathological characteristics of extraskeletal myxoid chondrosarcoma （EMC）. Methods The histopathology and immunophenotype of 2 case of EMC were studied and the corresponding articles were reviewed in order to analyse its diagnosis and differential diagnostic factors. Results One tumor occurred in left abdominal wall and another in right hip. Microscopically, both the neoplasms showed a lobulate pattern, which consisted of reticular cords of oval, short spindle, or polygonal cells with mild nuclear variation, embedded into an abundant myxoid stroma. Both of the tumor ceils were positive for vimentin and S-100, and mean Ki-67 activity was less than 2%. Conclusions EMC can be subdivided into a conventional well-differentiated and a cellular high-grade EMC. Both have specific histology and molecular genetic characteristics, but lack a characteristic immunophenotype. Ki-67 activity contributes to prognosis.